Image forming apparatus and image forming method

Abstract

For performing double-side printing, an image forming apparatus forms an image on one side of a sheet and then reverses the sheet if the sheet has not been reversed, forms an image on the other side of the sheet and then reverses the sheet if the sheet has been reversed once, and performs idle conveyance in which an image is not formed on a sheet and then discharges the sheet if the sheet has been reversed twice. According to the image forming apparatus and a method of forming an image by this apparatus, procedures of image formation by a user can be prevented from becoming troublesome and the sheets can be discharged in order of the originals.

What is claimed is:  
     
       1. A method for forming an image on one side of a sheet using an image forming apparatus which comprises: 
       an image forming unit for forming an image on a sheet;  
       a conveying unit for conveying the sheet to the image forming unit;  
       a reversal unit for reversing the sheet;  
       a control unit for determining whether the sheet is to be reversed or not and controlling the conveying unit and the reversal unit so as to reverse the sheet and convey the sheet to the image forming unit when it has been determined that the sheet is to be reversed; and  
       an obtaining unit for obtaining information on whether an image is to be formed on one side of the sheet or both sides thereof,  
       the control unit being capable of performing operations of:  
       determining whether an image is to be formed or not on the sheet conveyed to the image forming unit;  
       controlling the conveying unit and the image forming unit to convey the sheet to the image forming unit and to form the image on the sheet when it has been determined that an image is to be formed; and  
       controlling the conveying unit to convey the sheet to the image forming unit when it has been determined that an image is not to be formed,  
       wherein the control unit determines whether an image is to be formed or not on the sheet conveyed to the image forming unit when the obtaining unit has obtained information that an image is to be formed on one side of the sheet,  
       the method comprising steps of:  
       conveying a sheet to the image forming unit by the conveying unit with one side of the sheet facing toward the image forming unit;  
       reversing the sheet by the reversal unit;  
       conveying the sheet to the image forming unit by the conveying unit; and  
       forming an image on the other side of the sheet by the image forming unit.